This one's a lot easier to work algebraically. You could get it by trial an error or course, but its easy if you think of one number being just x and the other number being (40-x)
so for example if the number was 10 then the other number would be (40 - 10) or 30
*this is pretty close if you check 5(10) = 50 2(30) = 60 which is a 10 difference and not a 3 through trial and error you could get the right answer just switching out a new number
Algebraically:
So 2 times the 1st number lets use (40-x) since multiply by 2 with this is easier than by 5
2 (40 - x) is "equal" to
3 more than 5 times another number (x)
or 5x + 3
altogether we have 2(40-x) = 5x + 3
80 - 2x = 5x + 3
77 = 7x
x = 11
so 1 number is 11 and the other number is (40 - 11) or 29
check it--- 2(29) = 58 5(11) = 55 and indeed they are 3 apart
Monday, March 10, 2008
Number Problem 5 Solution
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thanks a lot
ReplyDeletethe answers should be 74/7 and 206/7,
ReplyDelete....
sorry thats incorrect -- those numbers added together do equal 40 but they dont follow the other stipulations of the problem ---> (206/7) * 2 which is 58.8571429 is not 3 more than (74/7) * 5 which is 52.8571429 ---> its 6 more ! So close -- but how did you get these numbers? I'm curious since it is close.
ReplyDeleteyeah its ok to commit mistakes, at least you have the problem,....
ReplyDeleteI don't think that person will be back to see your comment but I'm sure he appreciates it wherever he may be....
ReplyDeleteits inorrect....hope you understand....
ReplyDeleteNo I dont -- whats incorrect ?
ReplyDeleteim looking for the definition not the blah blah to be prank with you guys we need proper information no some chit chat thank you pls understand this
ReplyDeleteits correct..
Deletelet the two numbers be equal to x and y
(equation 1): the sum of the two numbers is equal to 40: x+y=40 (eq.1)
(equation 2): twice the first number... : 2x
...is... : =
...3 more than... : 3+
...5 times the other number...: 5y
: 2x=3+5y (eq.2)
equation 1 can also be expressed as: x=40-y
so substituting it with the (x) in equation 2 would result to another equation which is: 2(40-y)=3+5y
80-2y=3+5y
5y+2y=80-3
7y=77
y=11
solve for x by substituting the value of y in any of the two equations:
(equation 1): x+y=40
x+11=40
x=40-11
x=29
the two numbers are 11 & 29
if you're still in doubt encode the two equations on a CASIO fx-991 or 570 ES and use its equation function to check if the answer is correct..
...
ReplyDelete